Code review

Author: nex3

sdk/lib/js_interop/js_interop.dart

@@ -542,7 +542,7 @@ extension type JSSymbol._(JSSymbolRepType _jsSymbol) implements JSAny {
   /// the symbol itself.
   @Since('3.11')
   JSSymbol([String? description]) =>
-      description == null ? _constructSymbol() : _constructSymbol(description);
+      _jsSymbol = description == null ? _constructSymbol() : _constructSymbol(description);
 
   /// Searches for an existing symbol in a runtime-wide symbol registry with the
   /// given key and returns it if found.
@@ -551,7 +551,7 @@ extension type JSSymbol._(JSSymbolRepType _jsSymbol) implements JSAny {
   /// registry, and returns it.
   @Since('3.11')
   @JS('for')
-  external static JSSymbol forKey(String key);
+  external static JSSymbol forKey(String key;
 
   /// `Symbol.asyncDispose` from the ECMAScript [explicit resource management]
   /// feature.